Using Triploid Grass Carp to Control Aquatic Vegetation

Invasive aquatic weeds can create major impacts on freshwater ecosystems. One of the primary reasons invasives are able to thrive, spread rapidly, and outcompete native species is that the environmental checks and predators that control these species in their natural settings are lacking in the ecosystems and habitat in which they become introduced.

The subsequent damages they cause occur on many ecological levels including competition for food or habitat (feeding, refuge, and/or spawning), direct predation and consumption of native species, introduction of disease or parasites, and other forms of disruption that lead to the replacement of the native species with the invasive species. As a result, invasives often cause serious harm to the environment, the economy, and even human health.

Some of the more commonly occurring non-native aquatic plant species that impact East Coast lakes, ponds, and reservoirs include curly-leaf pondweed, eurasian watermilfoil, hydrilla, and water chestnut.

The introduction of triploid grass carp to freshwater lakes and ponds can be an effective solution and natural alternative to managing and mitigating aquatic weed growth. When stocked at a proper rate, at correct sizes, targeting proper plant species, and the right time, triploid grass carp can reduce or eliminate the need for chemical treatment of the water to control aquatic vegetation.

Originally from Asia, grass carp have been imported to the United States since the 1960s to intentionally release into controlled freshwater environments for aquatic plant control. Grass carp, which rely almost entirely on aquatic plants for their diet, prefer to eat many of the non-native aquatic plant species that negatively impact freshwater environments, including the aforementioned pondweed species and watermilfoil.

Triploid Grass Carp in Woodridge Lake

Woodridge Lake is a beautiful 385-acre freshwater lake tucked away in the hills of Litchfield County, Connecticut. The lake, which is fed by the Marshepaug River, is a man-made resource, with a dam at one end that allows the level of the lake to be controlled.

Woodridge Lake Property Owners’ Association (WLPOA) closely monitors the lake, conducting water sample testing on a weekly basis. As with all waterbodies, the lake experiences aquatic weed growth, some years worse than others due to a variety of factors including climate change.

As a method to naturally mitigate aquatic weed growth, WLPOA plans to introduce triploid grass carp to the waterbody. A study by the Connecticut Agricultural Experiment Station states that grass carp is “the only biological control used successfully in Connecticut.”

Since the grass carp are an introduced species, only triploid grass carp, which are sterile, can be used. This eliminates the possibility that the stocked fish can reproduce and overpopulate the lake, or if any were to escape the lake they could not affect other waterbodies. As an additional measure of protection, to ensure that the carp remain in the lake, a screen, or emigration control device, is required. Princeton Hydro, in partnership with WLPOA, Rowledge Pond Aquaculture, and CTDEEP recently completed the installation of a carp screen.

The screen, which was custom designed by Princeton Hydro, is located in the outlet structure of the Woodridge Lake Dam, downstream of the spillway crest and within the concrete stilling basin of the spillway structure. Subsequently, the installation and operation of the carp screen will have no impact on spillway capacity or water surface elevations at the spillway crest. In addition, there will be no impact on the flow capacity or the water surface elevations of the Marshepuag River downstream of the dam outlet structure.

The emigration control device is a modular, vertical-bar screen composed of eight sections. A modular screen design was chosen to facilitate off-site fabrication and easier installation, as well as repair of an individual section, if necessary. Installed, all eight sections transect the entire 40-foot width of the spillway structure.

WOODRIDGE LAKE CARP EXCLUSION DEVICE DESIGN by Princeton Hydro

The carp screen was specifically designed to be easy to operate and maintain, minimizing clogging and facilitating easy cleaning from the downstream side of the screen during a range of flows. The operation and maintenance plan also consists of inspections every three months and precipitation-based inspections conducted by the WLPOA staff.

Overall, the use of grass carp will help Woodridge Lake manage aquatic weed growth in a natural way and maintain a healthy and vibrant lake environment for years to come.

To learn more about Rowledge Pond Aquaculture, the oldest private fish hatchery in Connecticut, go here: rowledgepond.com. For more information about Princeton Hydro’s lake management services, go here: bit.ly/pondlake.

NJDEP Releases Updated Guidance for Harmful Algal Blooms

Last summer, 39 of New Jersey’s lakes were plagued with toxic algae outbreaks, also known as harmful algae blooms or HABs, causing major water quality degradation, beach closures and health advisories. In response, the NJDEP implemented a unified statewide approach to addressing HABs in freshwater recreational waters and sources of drinking water, and protecting the public from risks associated with exposure to cyanobacteria.

Last week, NJDEP announced a new component to its statewide Cyanobacterial HAB Response Strategy: a color-coded health alert index that provides precise recreational use recommendations for impacted waterbodies based on levels of cyanobacteria and/or cyanotoxins present. The index has six tiers – NONE, WATCH, ALERT, ADVISORY, WARNING, and DANGER – each providing recommendations on the specific activities that should or should not be pursued based on water monitoring results.

“Princeton Hydro is proud to be one of the contributing factors in the development of the Updated Guidance for HABs,” said said Dr. Fred Lubnow, Director of Aquatic Resources for Princeton Hydro. “We feel this updated protocol will provide the necessary and objective information for State and local organizations to make informed and rational decisions, based on sound and scientifically-based data, on how to deal with HABs in a recreational setting.

Princeton Hydro and Clean Water Consulting are the technical advisers for the New Jersey Lake Group, who have met a number of times over the last 8 to 9 months to discuss the State’s guidance on dealing with HABs.  In late 2019, on behalf of the New Jersey Lake Group, Princeton Hydro and Clean Water Consulting developed a White Paper providing recommended changes for consideration to NJDEP’s Recreational Response Strategy to HABs.

“I’m proud to say that many of the provided recommendations were integrated into NJDEP’s Updated Guidance for HABs,” explained Dr. Lubnow.

WATCH
(Suspected or confirmed HAB with potential for allergenic and irritative health effects)
This warning will be posted when HAB cell counts exceed 20,000. In this scenario, public beaches remain open, but the index instructs the public to use caution, provides information on the potential less serious health effects, and allows for more informed decision-making.

ALERT
(Confirmed HAB that requires greater observation due to increasing potential for toxin production)
This warning indicates a public bathing beach closure only and is posted when a HAB has been confirmed with cell counts between 40,000 and 80,000 and no known toxins above the public threshold. Beaches remain open (dependent upon local health authority) and monitoring for future toxin production should be increased.

ADVISORY
(Confirmed HAB with moderate risk of adverse health effects and increased potential for toxins above public health thresholds)
Signs will be posted for this warning level when cell counts exceed 80,000 or when toxin levels exceed 3 micrograms per milliliter of microcystins. Public bathing beaches will be closed, but the waterbody will remain accessible to some “secondary contact” activities, like boating.

WARNING and DANGER
(Confirmed HAB with high risk of adverse health effects due to high toxin levels)
and (Confirmed HAB with very high risk of adverse health effects due to high toxin levels)
These tiers are designed to alert the public to the presence of HABs that are producing very high levels of toxins which justify additional caution. In some instances, the entire waterbody may be closed for all public use. New Jersey has experienced approximately 12 “warning level” HAB events over the last 3 years; monitoring has never indicated a “danger level” HAB event.

According to their press release, NJDEP is committed to working with local officials to implement the index and get signage posted at lakes throughout the state as soon as possible.

In order to create the health index, NJDEP scientists carefully reviewed HABs data collected over the last three years by Lake Hopatcong Commission, Lake Hopatcong Foundation, Princeton Hydro, and other sources. The tiered warning system will enable lake communities, residents and visitors to make more individualized decisions about what risks they are willing to take and what activities they feel comfortable engaging in at the various levels of HABs.

In the coming days, the NJDEP’s Harmful Algal Bloom website will be updated to include the new health index and accompanying signage, relevant monitoring data, and other information for each of the impacted bodies of water, as well as an updated HAB Monitoring and Response Strategy. For now, you can read the full press release and additional information here: https://www.nj.gov/dep/newsrel/2020/20_0023.htm.

To learn more about HABs, check out our recent blog:

Identifying, Understanding and Addressing Harmful Algae Blooms

Bloomfield: Restoration Efforts Transforming Industrial Site Into Thriving Public Park

A densely developed, flood-prone, former industrial site in Bloomfield, New Jersey is being transformed into a thriving public park and 4.2 acres of wetlands. This is thanks to the Third River Floodplain Wetland Enhancement Project, which broke ground in March of 2019. The project will restore valuable ecological functions and natural floodplain connection, enhance aquatic and wildlife habitat, and increase flood storage capacity for urban stormwater runoff.

The project team has already made tremendous progress at the site, which is located along the Third River and Spring Brook, two freshwater tributaries of the Passaic River. Princeton Hydro is serving as the ecological engineer to Bloomfield Township; our scientists and engineers have assisted in obtaining grants, collected background ecological data through field sampling and surveying, created a water budget, completed all necessary permitting, designed both the conceptual and final restoration plans, and continues to conduct construction oversight during the implementation of this important urban wetland creation project.

The project team recently utilized a drone to document the significant progress being made:

 

View of the construction progress with the proposed wetland to the upper half of the photo. Photo provided by Creamer Environmental.

View of the construction progress with the proposed wetland to the upper half of the photo. Photo provided by Creamer Environmental.

Close-up view of the wetland construction progress. Note the hummocks and hollows created with the wetland soil as well as the habitat features constructed of trees and natural rock uncovered during the excavation process. Photo provided by Creamer Environmental.

Close-up view of the wetland construction progress. Note: the hummocks and hollows created with the wetland soil as well as the habitat features constructed of trees and natural rock uncovered during the excavation process. Photo provided by Creamer Environmental.

Nearly complete grading of the proposed wetland. Note the hummocks and hollows created with the wetland soil. Photo provided by Creamer Environmental.

Nearly complete grading of the proposed wetland. Note: the hummocks and hollows created with the wetland soil. Photo provided by Creamer Environmental.

Over 500 trees and shrubs have been planted in the new wetland with additional trees and shrubs planted along Lion Gate Drive and in existing woodlands. The selected native plant species all provide important wildlife value, including providing food and shelter for migratory birds. Enviroscapes was contracted to install all of the trees and wetland plants at this site and has nearly finished planting efforts:

Removing invasive species and replacing them with native plants, shrubs and trees sets the stage for a flourishing native plant community year after year.

Removing invasive species and replacing them with native plants, shrubs and trees, sets the stage for a flourishing wetland habitat.

The project is progressing quickly as the weather warms. Nearly all of the plantings have been installed and seeding is happening in the next two weeks.

This green infrastructure project will re-establish the natural floodplain wetland and riparian plant communities.

This green infrastructure project will re-establish the natural floodplain wetland and riparian plant communities.

We’re excited to see what the restoration will look like when it’s all finished. Check out additional photos below and stay tuned for project updates!

To learn more, check out the full story below:

Urban Wetland Restoration to Yield Flood Protection for Bloomfield Residents

Understanding and Addressing Invasive Species

Photo from: New York State Department of Environmental Conservation, water chestnut bed at Beacon

Spring is officially here! Tulips will soon be emerging from the ground, buds blossoming on trees and, unfortunately, invasive plant species will begin their annual growing cycle. No type of habitat or region of the globe is immune to the threat of invasive species (“invasives”). Invasives create major impacts on ecosystems throughout the world, and freshwater ecosystems and estuaries are especially vulnerable because the establishment of such species in these habitats is difficult to contain and reverse.

This blog provides an introduction to invasive aquatic species, including information that will help you prevent the spread of invasives in the waterways of your community.

Defining Invasive Species

Invasive species can be defined as non-native occurring in an ecosystem that is outside its actual natural or native distributional range. Although the colonization of an ecosystem by non-native species can occur naturally, it is more often a function of human intervention, both deliberate and accidental. For aquatic ecosystems some species have become established as a result of the aquarium trade, fish culture practices and/or transport of plants and animals in the bilge and ballast water of trans-oceanic shipping vessels.

One of the primary reasons invasives are able to thrive, spread rapidly, and outcompete native species is that the environmental checks and predators that control these species in their natural settings are lacking in the ecosystems and habitat in which they become introduced. The subsequent damages they cause occur on many ecological levels including competition for food or habitat (feeding, refuge and/or spawning), direct predation and consumption of native species, introduction of disease or parasites, and other forms of disruption that lead to the replacement of the native species with the invasive species. As a result, invasives very often cause serious harm to the environment, the economy, and even human health. A prominent example is the Emerald Ash Borer, a non-native, invasive beetle that is responsible for the widespread death of ash trees.

As noted above, there are a large number of aquatic invasive species. Some of the more commonly occurring non-native aquatic plant species that impact East Coast lakes, ponds and reservoirs include:

Understanding How Invasives Spread

Either intentionally or unintentionally, people have helped spread invasives around the globe. This is not a recent phenomenon but rather something that has been occurring for centuries. “Intentional introductions,” the deliberate transfer of nuisance species into a new environment, can involve a person pouring their home aquarium into a lake or deliberate actions intended to improve the conditions for various human activities, for example, in agriculture, or to achieve aesthetics not naturally available.

Photo by: Tom Britt/CC Flickr, zebra Mussels adhered to a boat propeller“Unintentional introductions” involve the accidental transfer of invasives, which can happen in many ways, including aquatic species attached to the hull of boats or contained in bilge and ballast water. A high-profile example is the introduction of zebra mussels to North America. Native to Central Asia and parts of Europe, zebra mussels accidentally arrived in the Great Lakes and Hudson River via cargo ships traveling between the regions. The occurrence, density, and distribution of Zebra mussels occurred at an alarming rate, with the species spreading to 20 states in the United States and to Ontario and Quebec in Canada. Due to their reproductive fecundity and filter-feeding ability, they are considered the most devastating aquatic invasive species to invade North American fresh waters. They alter and diminish the plankton communities of the lakes that they colonize leading to a number of cascading trophic impacts that have especially negative consequences on fisheries. Zebra mussel infestations have also been linked to increased cyanobacteria (bluegreen algae) blooms and the occurrence of harmful algae blooms (HABs) that impact drinking water quality, recreational use, and the health of humans, pets, and livestock.

Additionally, higher than average temperatures and changes in rain and snow patterns caused by climate change further enable some invasive plant species to move into new areas. This is exemplified by the increased northly spread of hydrilla (Hydrilla verticillate), a tropical invasive plant species that has migrated since its introduction in Florida in the 1950s to lakes, rivers, and reservoirs throughout the U.S.

Regardless of how any of these invasive species first became established, the thousands of terrestrial and aquatic invasive species introduced into the U.S. have caused major ecological, recreational and economic impacts.

Measuring the Impacts of Invasives

After habitat loss, invasive, non-native species are the second largest threat to biodiversity. According to The Nature Conservancy, “Invasive species have contributed directly to the decline of 42% of the threatened and endangered species in the United States. The annual cost to the nation’s economy is estimated at $120 billion a year, with over 100 million acres (an area roughly the size of California) suffering from invasive plant infestations. Invasive species are a global problem — with the annual cost of impacts and control efforts equaling 5% of the world’s economy.”

Of the $120 billion, about $100 million per year is spent on aquatic invasive plant control to address such deleterious issues as:

  • Human health (West Nile Virus, Zika Virus)
  • Water quality impacts (Canada geese)
  • Potable water supplies (Zebra mussel)
  • Commercial fisheries (Snake head, lamprey, Eurasian ruffe, round goby)
  • Recreational activities (Eurasian watermilfoil, water chestnut, hydrilla)
  • Biodiversity (Purple loosestrife, common reed, Japanese knotweed)

Invasive species can change the food web in an ecosystem by destroying or replacing native food sources. As the National Wildlife Federation explains, “The invasive species may provide little to no food value for native wildlife. Invasive species can also alter the abundance or diversity of species that are important habitat for native wildlife. Additionally, some invasive species are capable of changing the conditions in an ecosystem, such as changing soil chemistry…”

Addressing Invasives

Our native biodiversity is an irreplaceable and valuable treasure. Through a combination of prevention, early detection, eradication, restoration, research and outreach, we can help protect our native heritage from damage by invasive species.

What Can We Do?

  • Reduce the spread
  • Routinely monitor
  • Document and report
  • Spread the word

Reducing the Spread:
The best way to fight invasive species is to prevent them from occurring in the first place. There are a variety of simple things each of us can do to help stop the introduction and spread of invasives.

  • Plant native plants on your property and remove any invasive plants. Before you plant anything, verify with your local nursery and check out this online resource for help in identifying invasive plants.
  • Thoroughly wash your gear and watercraft before and after your trip. Invasives come in many forms – plants, fungi and animals – and even those of microscopic size can cause major damage.
  • Don’t release aquarium fish and plants, live bait or other exotic animals into the wild. If you plan to own an exotic pet, do your research to make sure you can commit to looking after it. Look into alternatives to live bait.

Monitoring:
The Lake Hopatcong Foundation Water Chestnut prevention brochureInvasive plant monitoring is one of the most valuable site­-level activities people can support. Contact your local watershed organizations to inquire about watershed monitoring volunteer opportunities. For example, the Lake Hopatcong “Water Scouts” program was established to seek out and remove any instances of the invasive water chestnut species.

If you are a lake or watershed manager, the best way to begin an invasive plant monitoring project is with an expert invasive plant survey to determine which invasives are most likely to be problematic in your watershed and identify the watershed’s most vulnerable areas. Contact us to learn more.

 

Documenting and Reporting:
It’s important to learn to identify invasive species in your area and report any sightings to your county extension agent or local land manager. For example, in New Jersey there is the Invasive Species Strike Team that tracks the spread of terrestrial and aquatic invasives and works with local communities in the management of these species. Additionally, consider developing a stewardship plan for your community to help preserve its natural resources. Princeton Hydro’s team of natural resource scientists can help you get the ball rolling by preparing stewardship plans focused on controlling invasive species and protecting the long-term health of open spaces, forests habitats, wetlands, and water-quality in your community.

Spreading the word:
Many people still don’t understand the serious implications of invasive species. Education is a crucial step in stopping the spread of invasives, which is why it’s so important to talk with your neighbors, friends and family about the hazards and ecological/economic impacts of invasive species.

Also consider talking with your community lake or watershed manager about hosting an educational workshop where experts can share their knowledge about invasives specific to your area and how best to address them. Princeton Hydro’s Director of Aquatic Programs Dr. Fred Lubnow recently gave a presentation to the Lake Hopatcong Foundation titled, “Invasive Species in Watershed Management.” View it here.

 

We encourage you to share this article and spread your invasive species knowledge so that together we can help stop the introduction and spread of invasive species.

Ecological Uplift in an Urban Setting

The City of Elizabeth, the fourth most populous in New Jersey, is not exactly the first place that comes to mind when envisioning a wild landscape. This bustling urban area is well known for its Port Newark-Elizabeth Marine Terminal and the Philips 66 Bayway Refinery, and sits at the intersection of several major roadways like the NJ Turnpike and the Goethals Bridge. The landscape, which was once teeming with dense wetlands and associated habitats, is now heavily urbanized with a vast mix of residential, commercial, and industrial properties. The largely channelized Elizabeth River courses through the city for 4.2 miles before draining into the Arthur Kill waterway. However, in this 14-square mile city, native flora and fauna are taking root again thanks to ecological restoration and mitigation efforts.

Urban landscapes like Elizabeth can pose significant challenges for restoration efforts, but they also provide an array of opportunity for significant ecological uplift.

In 2004, Princeton Hydro was retained to restore an 18-acre site adjacent to the Elizabeth Seaport Business Park, which is located in an area that was once part of a large contiguous wetland system abutting Newark Bay. The site was comprised of a significantly disturbed mosaic of wetland and upland areas and a monoculture of Phragmites australis, also known as Common Reed, on historic fill. Historic fill consists of non-native material, historically placed to raise grades, and typically contains contaminated material not associated with the operations of the site on which it was placed.

The highly invasive Phragmites australis had overtaken most of the wetland areas, and the upland woodland areas only contained four tree species, mostly Eastern Cottonwood, with very low wildlife value. The 18-acre site had huge potential but was significantly degraded and was being vastly underutilized. Overall, the mitigation plan focused on the enhancement of existing wetland and transition areas to increase the area’s wildlife value through the establishment of a more desirable, diverse assemblage of native species subsequent to eradication of non-native-invasive species.

2005 (Before Plantings)
2019
In 2004, Prologis hired Princeton Hydro to restore an 18-acre area adjacent to the Elizabeth Seaport Business Park, which a significantly disturbed and degraded mosaic of wetland and upland areas. This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced.

The freshwater wetland aspect of the mitigation plan, which included inundated emergent, emergent, and forested habitat, was designed to be a combination of wetland creation (2.40 acres) and enhancement (8.79 acres), emphasizing the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife food value.

The upland forest aspect of the mitigation plan involved the enhancement of 5.40 acres and creation of 1.45 acres of upland forest to foster the development of a species rich and structurally complex upland forest. The upland areas targeted for enhancement/creation consisted of areas where woody vegetation was lacking or forested areas that were dominated by eastern cottonwood.

2008
2019
The 18-acre site in Elizabeth, NJ had huge potential but was significantly degraded and was being vastly underutilized. The mitigation plan emphasized the establishment of more species rich wetlands in order to increase biodiversity and improve the site’s wildlife habitat value.

The project team worked to remove Phragmites australis from the site utilizing a combination of herbicide and mechanical removal techniques. Once the Phragmites australis was cleared, the team installed 27,000 two-inch native herbaceous plant plugs in the wetland portions of the mitigation site, and 2,705 native trees/shrubs throughout the site.

In order to ensure the continued success of the mitigation project, monitoring is regularly conducted at the site. A monitoring report conducted at the end of 2019 revealed a plethora of well-established habitat areas, a diverse community of plant and tree species, and a thriving, highly-functional landscape.

2004 (Before Plantings)
september 2019
In 2004, before the restoration work began, the site consisted of degraded Phragmites australis dominated wetlands and an urban woodland area dominated by Eastern cottonwood. The planting component of the mitigation project commenced in 2015, and the installation of all woody plant material began Fall 2015 and was completed in Fall 2016. The 2019 Monitoring Report revealed the plantings are well-established and the area is thriving.

Presently, the Elizabeth Seaport Business Park Mitigation Site boasts a variety of productive wildlife habitats that are rare in a highly urbanized setting and provides valuable ecosystem services, including sediment retention and roosting, foraging, and nesting opportunities for both resident and migratory bird species with over 150 bird species identified within the mitigation site.

2008
2019
The Elizabeth Seaport Business Park site was comprised of a monoculture of Phragmites australis, also known as Common Reed. The mitigation plan focused on enhancing the existing wetland by eradicating non-native-invasive plant species, like Phragmites, and establishing more diverse population of productive, native species with high ecological value.

This project serves as an example of how degraded urban areas can be successfully rehabilitated and the land’s natural function restored and enhanced.  If you’d like to learn more about this project from our Natural Resources Senior Project Manager Michael Rehman, check out the video of his presentation at the 2020 Delaware Wetlands Conference below.

We’re at the Delaware Wetlands Conference and our Senior Project Manager, Michael Rehman, is presenting on a successful urban wetland restoration in Elizabeth, NJ.

Posted by Princeton Hydro on Thursday, January 30, 2020

 

If you’re interested in learning more about our wetland restoration and mitigation services, go here!

Managing Invasive Phragmites and Restoring Natural Wetland Habitat

Non-native Phragmites australis, also known as Common Reed, is a species of perennial grass found across North America, especially along the Atlantic coast, in wetlands, riparian areas, shorelines, and other wet areas like roadside ditches and drainage basins. This aggressively invasive grass can grow up to 20 feet tall, in dense groupings, and tends to spread rapidly, quickly colonizing disturbed wetlands.

Once established, the invasive plant forms a monoculture with a dense mat, outcompeting native vegetation, lowering the local plant biodiversity, and displacing native animals. These landscape changes impair the natural function of the marsh ecosystem by altering its elevations and tidal reach. A higher, drier marsh leads to less vigorous growth of native salt marsh vegetation, allowing Phragmites australis to gain a stronger foothold and continue to take over.

USDA NRCS Plants Database phragmites illustrationPhragmites australis can also eliminate small, intertidal channels and obliterate pool habitat that offers natural refuge and feeding grounds for invertebrates, fish, and birds. The spread of invasive Phragmites australis also has negative impacts on land aesthetics and outdoor recreation by obscuring views and restricting access. And, each Fall, when Phragmites australis die off, the large concentrations of dry vegetation increase the risk of fast-spreading fires near highly populated residential and commercial areas.

Over the last century, there has been a dramatic increase in the spread of Phragmites australis, partly due to an increase in residential and commercial development that resulted in disturbances to wetlands. According to the U.S. Fish and Wildlife Service, the rapid spread of Phragmites australis in the 20th century can also be attributed to the construction of railroads and major roadways, habitat disturbance, shoreline development, pollution, and eutrophication.

Princeton Hydro has worked in areas throughout the East Coast to address and properly manage Phragmites australis in order to restore natural habitats and enhance plant diversity, wildlife habitat, and water quality. Two recent projects include the restoration of John A. Roebling Memorial Park in Hamilton and Pin Oak Forest Conservation Area in Woodbridge, New Jersey.

John A. Roebling Memorial Park

Mercer County’s John A. Roebling Memorial Park is home to the northernmost freshwater tidal marsh on the Delaware River, the Abbott Marshlands, an area containing valuable habitat for many rare species. Unfortunately, the area experienced a significant amount of loss and degradation, partially due to the introduction of the invasive Phragmites australis.

For Mercer County Park Commission, Princeton Hydro put together a plan to reduce and control the Phragmites australis, in order to increase biodiversity, improve recreational opportunities, and enhance visitor experience at the park. This stewardship project replaced the Phragmites australis with native species in order to reduce its ability to recolonize the marsh.

By Spring of this year, the team expects to see native species dominating the landscape from the newly exposed native seed bank with minimal Phragmites australis growth.

Pin Oak Forest Conservation Area

The Pin Oak Forest Conservation Area is a 97-acre tract of open space that contains an extremely valuable wetland complex at the headwaters of Woodbridge Creek. The site is located in a heavily developed landscape of northern New Jersey. As such, the area suffered from wetland and stream channel degradation, habitat fragmentation, ecological impairment, and decreased biodiversity due to invasive species, including Phragmites australis.

The site was viewed as one of only a few large-scale freshwater wetland restoration opportunities remaining in this highly developed region of New Jersey. A dynamic partnership between government agencies, NGOs, and private industry, was formed to restore the natural function of the wetlands complex, transform the Pin Oak Forest site into thriving habitat teeming with wildlife, and steward this property back to life.

This award-winning restoration project converted over 30 acres of degraded freshwater wetlands, streams and disturbed uplands dominated by invasive species into a species-rich and highly functional headwater wetland complex. The resulting ecosystem provides valuable habitat for wildlife including the state-threatened Black-crowned Night-heron and Red-headed Woodpecker. Biodiversity was also increased through invasive species management, which allowed establishment of native plants such as pin oak, swamp white oak, marsh hibiscus, and swamp rose. The restored headwater wetland system provides stormwater management, floodplain storage, enhanced groundwater recharge onsite, and surface water flows to Woodbridge Creek, as well as public hiking trails, all benefiting the town of Woodbridge.

Managing and Monitoring Phragmites

Scientific field research continues to be conducted in order to identify the best way(s) to manage and control the spread of Phragmites australis. Depending on the landscape and how established the Phragmites australis population is, there are several different methods that can be effective in reducing Phragmites australis infestations in order to allow for the regeneration of native wetland plant communities and protect fish and wildlife habitat.

Recently, a group of more than 280 scientists, resource managers and policy professionals gathered together at the Hudson River Estuary Program’s (HEP) annual conference to explore how natural and nature-based solutions (i.e. building living shorelines, enhancing tidal wetlands and stream corridors, and conserving vulnerable floodplains) can be used as critical tools for addressing the impacts of climate change while also protecting and enhancing critical habitat.

The conference included six interactive workshops and dynamic panel discussions. Christiana Pollack, GISP, CFM of Princeton Hydro, Terry Doss of New Jersey Sports and Exposition Authority, Kip Stein from New York City Parks, and Judith Weis of Rutgers lead a panel discussion, moderated by Lisa Baron from U.S. Army Corps Engineers, on “The Yin and Yang of Estuarine Phragmites Management” to share lessons learned over many years of combating invasive species, including how sea level rise is changing minds and techniques.

Together, representing decades of experience in Phragmites australis management and research, these experts presented the evolving nature of restoration for this habitat type, common control/management methodologies, and longterm management and monitoring strategies for this reed and other invasive species. During the panel discussion, Christiana made specific mention of the Roebling Park project as one example of successful strategies in action.

If you’re interested in learning more and seeing photos from a few recent Phragmites australis management projects, click below for a free download of Christiana’s full presentation.

Through a combination of prevention, early detection, eradication, restoration, research and outreach, we can protect our native landscapes and reduce the spread of invasive species. Learn more about our invasive species removal and restoration services.

 

Regional Watershed Planning: A Critical Strategy to Prevent HABs

Photo by @likethedeaadsea, submitted during our 2019 #LAKESAPPRECIATION Instagram Photo Contest.

Harmful Algae Blooms (HABs) were in the spotlight last summer due to the severe impacts they had on lakes throughout the country. Nation-wide, HABs caused beach closures, restricted lake usage, and led to wide-ranging health advisories. There were 39 confirmed harmful algal bloom (HAB) outbreaks in New Jersey alone.

As a reminder, HABs are rapid, large overgrowths of cyanobacteria. These microorganisms are a natural part of aquatic ecosystems, but, under the right conditions (primarily heavy rains, followed by hot, sunny days), these organisms can rapidly increase to form cyanobacteria blooms, also known as HABs. HABs can cause significant water quality issues; produce toxins that are incredibly harmful (even deadly) to humans, animals, and aquatic organisms; and negatively impact economic health, especially for communities dependent on the income of jobs and tourism generated through their local lakes.

“A property’s value near an infested lake can drop by up to $85,000, and waterside communities can lose millions of dollars in revenue from tourism, boating, fishing and other sectors,” reports Princeton Hydro President Geoff Goll, P.E.

Generally, the health of a private lake is funded and managed in isolation by the governing private lake association group. But, in order to mitigate HABs and protect the overall health of our local waterbodies, it’s important that we look beyond just the lake itself. Implementing regional/watershed-based planning is a critical step in preventing the spread of HABs and maintaining the overall health of our natural resources.

At the end of 2019, the Borough of Ringwood became the first municipality in New Jersey to take a regional approach to private lake management through a public-private partnership with four lake associations.

The Borough of Ringwood is situated in the heart of the New Jersey Highlands, is home to several public and private lakes, and provides drinking water to millions of New Jersey residents. In order to take an active role in the management of these natural resources, Ringwood hired Princeton Hydro, a leader in ecological and engineering consulting, to design a municipal-wide holistic watershed management plan that identifies and prioritizes watershed management techniques and measures that are best suited for immediate and long-term implementation.

Map showing the four private lakes involved in the Borough of Ringwood's regional holistic watershed management plan.

Funding for Ringwood’s Watershed-based Assessment is being provided by the New Jersey Highlands Council through a grant reimbursement to the Borough of Ringwood. The Highlands Council offers grant funding and assistance to support the development and implementation of a wide range of planning initiatives. Examples of the types of efforts that can be funded for municipalities and counties include:

  • Land Use and Development projects like sustainable economic development planning and green building and environmental sustainability planning;
  • Infrastructure projects like stormwater management and water use/conservation management;
  • Resource Management projects like habitat conservation, lake management and water quality monitoring; and
  • Recreation and Preservation projects like land preservation and stewardship, farmland preservation and agriculture retention, and historic preservation.

Chris Mikolajczyk, CLM, Princeton Hydro’s Aquatics Senior Project Manager and the Ringwood project’s lead designer, presented with Keri Green of the NJ Highlands Council, at a recent New Jersey Coalition of Lake Associations meeting. The duo showcased Ringwood’s unique approach, spread the word about available funding through the NJ Highlands Council, and encourage other municipalities to follow Ringwood’s lead in taking a regional approach to lake and watershed management.

Mikolajczyk said, “This regional approach to lake and watershed management is a no-brainer from a scientific, technical, and community point of view. Historically, however, municipal governments and private lake associations have rarely partnered to take such an approach. The hope is that the Borough of Ringwood efforts, funded by the New Jersey Highlands Council, will set a precedent for this logical watershed management strategy and open the door for future public-private partnerships.”

This integrated approach to watershed and lake management is an important preventative measure to improve water quality for millions of people and reduce potential future incidents of aquatic invasive species and harmful algal blooms throughout the region.

To learn more about NJ Highlands Council and available grant funding, go here.
To download a complete copy of the presentations given by Mikolajczyk and Green at the recent NJCOLA meeting, go here.
To learn more about Princeton Hydro’s pond, lake and watershed management services, go here.

 

Dr. Fred Lubnow of Princeton Hydro Featured in Magazine Article on Chautauqua Lake

The U.S. is home to thousands of lakes both natural and manmade. Lakes are incredibly important features in the landscape that provide numerous beneficial services, including domestic water supply, hydro-electric power, agricultural water supply, recreation, and tourism. They also provide essential habitat for fish, wildlife and aquatic organisms.

Lakes are complex and dynamic systems, each situated in a unique landscape context. Maintaining the ecological health of a lake is no easy feat. A lot goes on behind the scenes to maintain water quality and a balanced lake ecosystem. Successful, long-term lake management requires a proactive approach that addresses the causes of its water quality problems rather than simply reacting to weed and algae growth and other symptoms of eutrophication.

Chautauqua Magazine recently published an article about the science behind the management of Chautauqua Lake, which features our Director of Aquatic Programs Dr. Fred Lubnow. We’ve included an excerpt below. Click here to view the full article and photos:

Dr. Fred Lubnow is a scientist and director of aquatic programs at Princeton Hydro, a consulting organization based in Exton, Pennsylvania, that is often called on to support lake and watershed regions that want to develop a long-term plan for lake conservation.

He says that while his firm focuses on the development of data and intelligence to inform decision making in regard to freshwater ecosystems, his work is really about coalition building.

“As a scientist and a consultant, you learn over time that you are building a coalition stakeholders and determining what we can agree on to help everyone in the community,” Lubnow said.

Ten years ago, Princeton Hydro was hired to do some stream and inlet monitoring for various stakeholders at Chautauqua Lake. More recently, they’ve been contracted to conduct third-party monitoring of the impacts of the Spring 2019 herbicide applications in the south basin of Chautauqua Lake…

Continue reading!

 

Princeton Hydro is the industry leader in lake restoration and watershed management. We have conducted diagnostic studies and have developed management and restoration plans for over 300 lakes and watersheds throughout the country. This has included work for public and private recreational lakes, major water supply reservoir, and watershed management initiatives conducted as part of USEPA and/or state funded programs. For more information about our lake management services, go here: http://bit.ly/pondlake. 

Managing Urban Stormwater Runoff and Revitalizing Natural Habitat at Harveys Lake

Measuring 630+ acres, Harveys Lake, located in Luzerne County, Pennsylvania, just northeast of Wilkes-Barre, is the largest natural lake (by volume) within the Commonwealth of Pennsylvania, and is one of the most heavily used lakes in the area. It is classified as a high quality – cold water fishery habitat (HQ-CWF) and is designated for protection under the classification.

Since 2002, The Borough of Harveys Lake and the Harveys Lake Environmental Advisory Council  has worked with Princeton Hydro on a variety of lake management efforts focused around maintaining high water quality conditions, strengthening stream banks and shorelines, and managing stormwater runoff.

Successful, sustainable lake management requires identifying and correcting the cause of eutrophication as opposed to simply reacting to the symptoms of eutrophication (algae and weed growth). As such, we collect and analyze data to identify the problem sources and use these scientific findings to develop a customized management plan that includes a combination of biological, mechanical, and source control solutions. Here are some examples of the lake management strategies we’ve utilized for Harveys Lake:

 

Floating Wetland Islands

Floating Wetland Islands (FWIs) are an effective alternative to large, watershed-based natural wetlands. Often described as self-sustaining, FWIs provide numerous ecological benefits. They assimilate and remove excess nutrients, like nitrate and phosphorous, that could fuel algae growth; provide habitat for fish and other aquatic organisms; help mitigate wave and wind erosion impacts; and provide an aesthetic element. FWIs are also highly adaptable and can be sized, configured, and planted to fit the needs of nearly any lake, pond, or reservoir.

Five floating wetland islands were installed in Harveys Lake to assimilate and reduce nutrients already in the lake. The islands were placed in areas with high concentrations of nutrients, placed 50 feet from the shoreline and tethered in place with steel cables and anchored. A 250-square-foot FWI is estimated to remove up to 10 pounds of nutrients per year, which is significant when it comes to algae.

Princeton Hydro worked with the Harveys Lake Environmental Advisory Council and the Borough of Harveys Lake to obtain funding for the FWIs through the Pennsylvania Department of Environmental Protection (PADEP).

 

Streambank & Shoreline Stabilization

Harveys Creek

The shoreline habitat of Harveys Lake is minimal and unusual in that a paved road encompasses the lake along the shore with most of the homes and cottages located across the roadway, opposite the lake. In addition to the lake being located in a highly populated area, the limited shoreline area adds to the challenges created by urban stormwater runoff.

Runoff from urban lands and erosion of streambanks and shorelines delivers nutrients and sediment to Harveys Lake. High nutrient levels in the lake contribute to algal blooms and other water quality issues. In order to address these challenges, the project team implemented a number of small-scale streambank and inlet stabilization projects with big impacts.

The work included the stabilization of the streambank downstream for Harveys Lake dam and along Harveys Creek, the design and installation of a riparian buffer immediately along the lake’s shoreline, and selective dredging to remove sediment build up in critical areas throughout the watershed.

 

Invasive Species Management

Hydrilla (Hydrilla verticillata), an aggressively growing aquatic plant, took root in the lake in 2014 and quickly infected 250 acres of the lake in a matter of three years. If left untreated, hydrilla will grow to the water’s surface and create a thick green mat, which prevents sunlight from reaching native plants, fish and other organisms below. The lack of sunlight chokes out all aquatic life.

In order to prevent hydrilla from spreading any further, Princeton Hydro and SePRO conducted an emergency treatment of the impacted area utilizing the systemic herbicide Sonar® (Fluridone), a clay-based herbicide. SonarOne, manufactured by SePRO, blocks hydrilla’s ability to produce chloroplasts, which in turn halts the photosynthetic process. The low-concentration herbicide does not harm fish, wildlife or people using the lake. Surveys conducted after the treatment showed it was working – the hydrilla had turned white and was dying off. Additional Sonar treatments followed and efforts to eradicate hydrilla in the lake continue.

Dr. Fred Lubnow, our Director of Aquatic Programs, estimates complete eradication of the aquatic plant could take around five years. Everyone can do their part in preventing the spread of this and other invasive species. Boaters and lake users must be vigilant and remove all vegetation from the bottom of watercrafts and trailers.

 

Stormwater Best Management Practices (BMPs)

In 2009, Princeton Hydro developed a stormwater implementation plan (SIP) for Harveys Lake. The goal of the stormwater/watershed-based efforts was to reduce the lake’s existing annual total phosphorus load to be in full compliance with the established Total Maximum Daily Load (TMDL). This TMDL is related to watershed-based pollutant loads from total phosphorus (TP) and total suspended solids (TSS), which can contribute to algal blooms.

A number of structural urban runoff projects were implemented throughout the watershed. This includes the design and construction of two natural stream channel projects restoring 500 linear feet of tributaries and reducing the sediment and nutrient loads entering the lake. A series of 38 urban runoff BMPs, including nutrient separating devices and roadside infiltration, were installed in areas immediately adjacent to the lake to further reduce the loads of nutrients and other pollutants reaching the lake.

The photos below show a stormwater project that was completed in the Hemlock Gardens Section of the Watershed. Hemlock Gardens is a 28-acre section of land located in the southeastern portion of the watershed. It contains approximately 26 homes, has very steep slopes, unpaved dirt roads, and previously had no stormwater infrastructure in place.

Two structural stormwater BMPs were installed:

  • A nutrient separating baffle box, which utilizes a three-chamber basin with screens to collect leaf litter, grass clippings and trash
  • A water polishing unit that provides a platform for secondary runoff treatment

In 1994, Harveys Lake was identified as “impaired” by PADEP due to large algal blooms. In 2014, Harveys Lake was removed from the list of impaired waters. Project partners attribute the recovery of this lake to the stream restoration, urban runoff BMP implementation, and the use of in-lake nutrient reduction strategies.

The Harveys Lake Watershed Protection Plan Implementation Project proved that despite the lake being located in an urbanized watershed, it is possible to implement cost-effective green infrastructure and stormwater retrofit solutions capable of significantly decreasing pollutant loading to the lake.

To learn more about our lake and pond management services or schedule a consultation, visit: http://bit.ly/pondlake.

PHOTOS: #BagThePhrag Update from Roebling Park

We’re gearing up for another invasive species treatment event at Roebling Park!

Located in Hamilton Township, New Jersey, Mercer County’s John A. Roebling Memorial Park offers residents in the surrounding area a freshwater marsh with river fishing, kayaking, hiking, and wildlife-watching. The park contains the northernmost freshwater tidal marsh on the Delaware River, Abbott Marshland. Since the mid-1990s, many public and private partnerships have developed to help support the preservation of this important and significant marsh.

Our Field Operations Team was recently at the project site assessing present invasive species and re-evaluating access points for our treatment equipment. Check out these photos from their visit!

 

For more information on this marsh restoration project at John A. Roebling Park, visit our original project blog:

Restoring the Northernmost Freshwater Tidal Marsh on the Delaware River